向高手请教几道英语的解释句子（同义句转换）谢啦!

11. It's important for us to control the growth of population.
12. Mr.White didn't attend the meeting yesterday.
13. How much is a one-way ticket cost from Shenzhen to Beijing?
What is the price of a one-way ticket from Shenzhen to Beijing?
14. I am not sure when to start.
15. They are very friendly to each other.
16. How clever a boy Jim is!
17. Jack was here just now.
18.The student listened to the teacher carefully in class.
19.Summer comes after spring.
20. Tom asked the teacher if/whether the horse ran faster than the donkey.
英语牛人团

we should control the growth of population which is important
Mr.White was not attend the meaning yesterday

11. It is important for us to control the growth of population.
12.Mr.White didn't understand the meaning yesterday.
13.what's the price of a one-way ticket from Shenzhen to Beijin...